Comparison of Oxford Cognitive Screen and Montreal Cognitive Assessment feasibility in the stroke unit setting. A pilot study

Background: : Cognitive status evaluation is not routine in the acute stroke setting and there is no consensus on which neuropsychological tool is more feasible and informative. The aim of this pilot study was to compare the feasibility and acceptability of two brief cognitive tests, the Montreal Cognitive Assessment (MoCA) and the Oxford Cognitive Screen (OCS), in acute stroke, with a focus on patients' experience, administration time, and the cognitive data obtained. Methods: : Patients with a diagnosis of ischemic or hemorrhagic stroke or of transient ischemic attack admitted to two stroke units were included. The sample consisted of 34 participants (mean age ±SD 71.1 ± 16.1 years, 25 males). Within five days of onset, patients were evaluated by means of the MoCA and OCS by a trained neuropsychologist. Results: Both tests were feasible in the stroke unit setting and had a high level of acceptability by patients. MoCA test was fully completed by 25 patients, OCS by 21 patients. The OCS administration time was longer than that of the MoCA. However, OCS was perceived less demanding than MoCA by patients. Twenty patients completed both the MoCA and the OCS entirely, and only 2 of them did not show any impairment in both tests. Seventeen patients showed at least an impaired domain on the OCS and 15 patients presented with a MoCA global score below cut-off for cognitive impairment. Conclusions: Our preliminary study did not show a superiority of the OCS over the widely used MoCA, and suggests the need for further validation in larger samples of stroke patients, exploring tests accuracy in detecting cognitive post-stroke impairment

Prediction of Impaired Performance in Trail Making Test in MCI Patients With Small Vessel Disease Using DTI Data

Mild cognitive impairment (MCI) is a common condition in patients with diffuse hyperintensities of cerebral white matter (WM) in T2-weighted magnetic resonance images and cerebral small vessel disease (SVD). In MCI due to SVD, the most prominent feature of cognitive impairment lies in degradation of executive functions, i.e., of processes that supervise the organization and execution of complex behavior. The trail making test is a widely employed test sensitive to cognitive processing speed and executive functioning. MCI due to SVD has been hypothesized to be the effect of WM damage, and diffusion tensor imaging (DTI) is a well-established technique for in vivo characterization of WM. We propose a machine learning scheme tailored to 1) predicting the impairment in executive functions in patients with MCI and SVD, and 2) examining the brain substrates of this impairment. We employed data from 40 MCI patients with SVD and created feature vectors by averaging mean diffusivity (MD) and fractional anisotropy maps within 50 WM regions of interest. We trained support vector machines (SVMs) with polynomial as well as radial basis function kernels using different DTI-derived features while simultaneously optimizing parameters in leave-one-out nested cross validation. The best performance was obtained using MD features only and linear kernel SVMs, which were able to distinguish an impaired performance with high sensitivity (72.7%-89.5%), specificity (71.4%-83.3%), and accuracy (77.5%-80.0%). While brain substrates of executive functions are still debated, feature ranking confirm that MD in several WM regions, not limited to the frontal lobes, are truly predictive of executive functions

Sparse Decomposition and Modeling of Anatomical Shape Variation

Recent advances in statistics have spawned powerful methods for regression and data decomposition that promote sparsity, a property that facilitates interpretation of the results. Sparse models use a small subset of the available variables and may perform as well or better than their full counterparts if constructed carefully. In most medical applications, models are required to have both good statistical performance and a relevant clinical interpretation to be of value. Morphometry of the corpus callosum is one illustrative example. This paper presents a method for relating spatial features to clinical outcome data. A set of parsimonious variables is extracted using sparse principal component analysis, producing simple yet characteristic features. The relation of these variables with clinical data is then established using a regression model. The result may be visualized as patterns of anatomical variation related to clinical outcome. In the present application, landmark-based shape data of the corpus callosum is analyzed in relation to age, gender, and clinical tests of walking speed and verbal fluency. To put the data-driven sparse principal component method into perspective, we consider two alternative techniques, one where features are derived using a model-based wavelet approach, and one where the original variables are regressed directly on the outcome

Location, number and factors associated with cerebral microbleeds in an Italian-British cohort of CADASIL patients.

BACKGROUND AND PURPOSE: The frequency, clinical correlates, and risk factors of cerebral microbleeds (CMB) in Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) are still poorly known. We aimed at determining the location and number of CMB and their relationship with clinical manifestations, vascular risk factors, drugs, and other neuroimaging features in CADASIL patients. METHODS: We collected clinical data by means of a structured proforma and centrally evaluated CMB on magnetic resonance gradient echo sequences applying the Microbleed Anatomical Rating Scale in CADASIL patients seen in 2 referral centers in Italy and United Kingdom. RESULTS: We evaluated 125 patients. CMB were present in 34% of patients and their presence was strongly influenced by the age. Twenty-nine percent of the patients had CMB in deep subcortical location, 22% in a lobar location, and 18% in infratentorial regions. After adjustment for age, factors significantly associated with a higher total number of CMB were hemorrhagic stroke, dementia, urge incontinence, and statins use (this latter not confirmed by multivariate analysis). Infratentorial and deep CMB were associated with dementia and urge incontinence, lobar CMB with hemorrhagic stroke, dementia, and statins use. Unexpectedly, patients with migraine, with or without aura, had a lower total, deep, and lobar number of CMB than patients without migraine. DISCUSSION: CMB formation in CADASIL seems to increase with age. History of hemorrhagic stroke, dementia, urge incontinence, and statins use are associated with a higher number of CMB. However, these findings need to be confirmed by longitudinal studies

Relationship between progression of brain white matter changes and late-life depression: 3-year results from the LADIS study

Background: Brain white matter changes (WMC) and depressive symptoms are linked, but the directionality of this association remains unclear. Aims: To investigate the relationship between baseline and incident depression and progression of white matter changes. Method: In a longitudinal multicentre pan-European study (Leukoaraiosis and Disability in the elderly, LADIS), participants aged over 64 underwent baseline magnetic resonance imaging (MRI) and clinical assessments. Repeat scans were obtained at 3 years. Depressive outcomes were assessed in terms of depressive episodes and the Geriatric Depression Scale (GDS). Progression of WMC was measured using the modified Rotterdam Progression scale. Results: Progression of WMC was significantly associated with incident depression during year 3 of the study (P = 0.002) and remained significant after controlling for transition to disability, baseline WMC and baseline history of depression. There was no significant association between progression of WMC and GDS score, and no significant relationship between progression of WMC and history of depression at baseline. Conclusions: Our results support the vascular depression hypothesis and implicate WMC as causal in the pathogenesis of late-life depression.Full Tex